I'm pulling my hair out with my 93 Cummins. I was headed to the gas station the other night and I thought I heard it suck some air. It's done this before. The RPM's dropped and it took more throttle to get up to speed. I fueled up and things seemed fine. The next morning I fired it up and idled down the street. When I applied the brakes it bucked a few times, blew black smoke and died. I started it back up and went home. It has continued to stall out and act as if it's sucking air bubbles intermittently. Here is a video of what it's doing.
I have deleted the FSS, checked all fuel lines, changed fuel filter, plumbed to a fuel can, bled the injectors, bled the filter and changed the fuel pump. The filter bleeder bubbles a tiny bit when I first start pumping, but no signs of air after the initial pump or two. I'm starting to wonder if something has plugged the return line as I haven't checked that. Is something that would cause these issues? It was running pretty good at higher rpm's but it seems to be getting worse. Any thoughts on this? Much appreciated.
